Research Says This Way Of Eating May Impact Your Fertility—Doctors Reveal The Truth
Time-restricted eating (TRE) is having a moment in the sun, to say the least. The eating method—which involves consuming all your daily calories within a set number of hours—can help manage weight, but it may impact another unexpected aspect of your health: your fertility.
New research has shown that TRE, a form of intermittent fasting (IF), may improve fertility for those with polycystic ovary syndrome (PCOS). A 2025 review in Metabolism Open examined three studies to determine the relationship between IF, fertility, and PCOS and found that IF helped those with PCOS achieve more predictable ovulation schedules, which can increase the likelihood of pregnancy.
Plus, since fasting can help with weight loss, it can potentially improve fertility for those who are obese and may have hypertension and high cholesterol, which can negatively affect fertility, says Joshua Hurwitz, MD, an OB-GYN and reproductive endocrinologist at Illume Fertility in Connecticut.
However, fasting can also lead to nutritional deficiencies, which may disrupt one's hormonal balance and decrease egg quality, according to a 2024 study in Cureus Journal of Medical Science that looked at the association between nutritional deficiencies and subfertility. "Human health should be optimal going into pregnancy, and that can be hard to achieve when you are in a caloric deficit,' says Brittany Brown, RD, the founder of Feeding Babies, Nourishing Souls in Nova Scotia, Canada.
So, what's the real correlation between fasting and fertility? Experts weigh in on TRE and how it can affect your chances of conceiving.
Meet the experts: Joshua Hurwitz, MD, is a board-certified OB-GYN and reproductive endocrinologist and partner at Illume Fertility in Connecticut. Brittany Brown, RD, is the founder of Feeding Babies, Nourishing Souls in Nova Scotia, Canada. Suzanna Chatterjee, MD, is an OB-GYN based in Russellville, Arkansas. Eve Feinberg, MD, is a reproductive endocrinology and infertility specialist at Northwestern Medicine. Mel Spinella, RD, is a New York-based dietitian specializing in fertility and pregnancy nutrition and the founder of Well by Mel Nutrition.
A 2023 study in Free Radical Biology and Medicine looked at older mice to see how intermittent fasting impacts reproduction, and found that one month of fasting every other day improved the quality of developing eggs. The fasting lowered the amount of free radicals, molecules that can interfere with cellular processes, including cell division and reproduction, says Brown.
Still, Brown points out that this study was done in mice, and there's not enough evidence yet to claim that fasting could have the same effect on humans. 'Future research will hopefully uncover how this works, but for now, we need more data before making recommendations," she says.
A 2021 study in the Journal of Translational Medicine looked at 15 women between the ages of 18 and 31 who didn't ovulate. They participated in time-restricted feeding for five weeks, and afterward, 11 of the 15 participants experienced improved menstrual regularity.
Many people with PCOS produce high levels of insulin, which can lead to excess male hormones in the body (such as testosterone), preventing ovulation, Suzanna Chatterjee, MD, an OB-GYN based in Russellville, Arkansas explains. Eating stimulates insulin, so with fewer meal times, those with PCOS could experience fewer spikes of insulin, which could help manage those excess hormones.
TRE may help restore ovulation and improve fertility outcomes without the need for medication for those with PCOS, adds Eve Feinberg, MD, a reproductive endocrinology and infertility specialist at Northwestern Medicine. Still, fasting won't help everyone with PCOS—in the aforementioned study, four of the 15 women with the condition didn't experience better menstrual regularity.
So, more research is needed on the connection between PCOS and fasting.
Those with obesity are predisposed to have conditions such as hypertension, high cholesterol, and diabetes, which can 'impair natural fertility, as well as lower the success rates of fertility treatment,' says Dr. Hurwitz. 'Even a modest weight loss of 5 to 10 percent can improve ovulation and hormone balance.'
Still, weight loss is only one piece of the puzzle. 'Not everyone who is overweight will have trouble conceiving,' and vice versa, he adds.
Plus, studies on TRE's effectiveness as a weight loss tool are conflicting. A 2021 study in Nutrition & Diabetes, which followed 78 men and women with obesity, found subjects had 'meaningful weight loss' after following a TRE plan for eight weeks. But a 2023 study of 547 adults over six months in the Journal of the American Heart Association found that TRE did not help subjects lose weight. So, more research is needed.
Experts say those with PCOS and those who are obese may benefit from TRE. But for the general population, there are other better ways to improve one's fertility, such as exercising and eating healthy, balanced meals. 'Eating enough, especially nutrient-dense foods throughout the day, is essential for a healthy menstrual cycle,' as well as ovulation, says Mel Spinella, RD, a New York-based dietitian specializing in fertility and pregnancy nutrition and the founder of Well by Mel Nutrition.
Brown also advocates for a more natural, eat-when-you're-hungry approach to mealtimes for those who are actively trying to conceive—even for those with PCOS—and particularly once pregnancy is possible or confirmed. 'Reliable and consistent energy intake is essential for reproductive health, especially in the early moments of pregnancy,' she says. She says that her female clients generally find more success conceiving when they follow less restrictive diets that focus on consuming healthy foods.
Plus, the research on fasting and fertility is still in the early phases. 'Ultimately, there is a need for large-scale, long-term randomized control trials to truly understand the long-term impacts of TRE on fertility,' Spinella says.
When it comes to intermittent fasting, there are a ton of different schedules breaking down when to eat, from the more flexible 14:10 (14 hours of fasting and 10 hours of eating), to the more restrictive 20:4 plan (20 hours of fasting and four hours of eating).
Brown says intense schedules like 20:4 can make it difficult to meet daily nutrient needs, which are essential before getting pregnant. Meanwhile, a 12:12 approach is more flexible and easier to follow for success. For instance, eating only between 7 a.m. and 7 p.m. might naturally reduce late-night snacking on ultra-processed foods without being overly rigid. However, Dr. Chatterjee recommends following a 16:8 schedule, particularly for women with PCOS who are hoping to regulate their cycle.
Before beginning any fasting schedule, it's always recommended that you check in with your medical provider to see what they think, Dr. Hurwitz says. At the end of the day, everyone is different and 'there's no one-size-fits-all answer,' to how your body will feel during your fertility journey, Brown says. The way you eat is totally up to you and what will make your body feel best.
You Might Also Like
Jennifer Garner Swears By This Retinol Eye Cream
These New Kicks Will Help You Smash Your Cross-Training Goals
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Washington Post
35 minutes ago
- Washington Post
How an empty North Carolina rural hospital explains a GOP senator's vote against Trump's tax bill
WASHINGTON — Though patients don't rush through the doors of this emergency room anymore, an empty hospital in Williamston, North Carolina, offers an evocative illustration of why Republican Sen. Thom Tillis would buck his party leaders to vote down President Donald Trump's signature domestic policy package. Martin General is one of a dozen hospitals that have closed in North Carolina over the last two decades. This is a problem that hospital systems and health experts warn may only worsen if the legislation passes with its $1 trillion cuts to the Medicaid program and new restrictions on enrollment in the coverage.
Forbes
37 minutes ago
- Forbes
MAHA's Focus On Improving Nutrition Is At Odds With Trump Policies
WASHINGTON, DC - MAY 22: U.S. President Donald Trump and Health and Human Services Secretary Robert ... More F. Kennedy Jr. attend an event introducing a new Make America Healthy Again Commission report in the East Room of the White House on May 22, 2025 in Washington, DC. The commission, which is tasked with studying the potential causes for the "childhood chronic disease crisis," recommends reassessing the nation's childhood vaccine schedule, scrutinizing ultra-processed foods and studying pesticides used in commercial farming. At the same time, the Trump administration has proposed a FY2026 budget of $94 billion for the Department of Health and Human Services — a reduction of about 26-percent from the 2025 level — cutting programs and staff at the National Institutes of Health and the Centers for Disease Control and Prevention. (Photo by) In introducing the first Make America Healthy Again Commission report, Health and Human Services Secretary Robert F. Kennedy Jr. said the focus is childhood chronic disease prevention, with a particular emphasis on nutrition. But several key Trump administration policies appear to be inconsistent with this goal. And the report does not include several notably absent topics that are known to cause certain chronic diseases. The first MAHA Commission report released in May identifies multifarious drivers of childhood chronic disease, including poor diet and specifically the shift over time to ultra-processed foods, overuse of pesticides in agriculture, food dyes in products for sale in grocery stores and a cumulative overload of chemicals in the environment. The document offers a potpourri of high-level policy recommendations to counter these trends. In a tweet, Kennedy touted on June 19th that 'artificial dyes and additives are being removed from America's food supply.' Thus far, however, only Red Dye No. 3 has been banned and this occurred under the Biden administration. Manufacturers have until Jan. 2027 to remove this specific dye from their products. The HHS budget for 2026 proposes $14 billion in discretionary funding for programs that aim to reverse what Secretary Kennedy calls the 'chronic disease epidemic,' as it consolidates entities housed under the Centers for Disease Control and Prevention into the Administration for a Healthy America, namely the National Center for Chronic Disease Prevention and Health Promotion and the Division of Nutrition, Physical Activity, and Obesity. AHA is being called the 'primary federal agency committed to transforming the health of all Americans by addressing the root causes of chronic disease, promoting preventive care, advancing mental health and substance use services, and increasing access to a healthy environment and foods.' But only $2 million is being allocated to nutrition, an amount experts suggest is inadequate. They believe the figure should be doubled to at least $4 billion to achieve the objectives laid out by Secretary Kennedy. And despite the MAHA report raising concerns about American agricultural products, other Trump cabinet officials insist that the nation's food supply is safe. Differences in views on glyphosate, a commonly used chemical sprayed on crops, illustrate the disconnect. Glyphosate is cited in the report as a major contributor in the rise of chronic disease. It is a substance that may cause serious health problems, including cancer. But the administrator of the Environmental Protection Agency, Lee Zeldin, doesn't want to further regulate glyphosate. On food safety generally, Kennedy appears to be at odds with director Zeldin's decisions to deregulate pesticides. The MAHA report makes dozens of references to dietary guidelines and food standards in Europe that prohibit the use of certain pesticides in agriculture. However, Zeldin has promised no more regulations, arguing that European-style mandates would stifle economic growth. Furthermore, Congress and the Trump administration back cuts to assistance programs, such as the Supplemental Nutrition Assistance Program, that would seem to undermine efforts to improve people's access to food, whether of high or low quality. Food and diet researchers are also criticizing the direction the National Institutes of Health are going in possibly stifling debate regarding the merits and demerits of different foods. According to STAT News, more than 70 top U.S. nutrition scientists signed a letter last month demanding that NIH director Jay Bhattacharya address alleged censorship at the agency, writing that their colleagues 'need the freedom to present their findings in scientific meetings without political oversight, and to author and co-author freely in the scientific literature.' The letter is in part a response to censorship allegations from former top NIH nutrition scientist Kevin Hall, whose research on ultra-processed foods was cut short when he resigned in April, complaining of interference from his superiors. The MAHA Commission report attributes adverse health effects to nutrient depletion owing to 'ultra-processed grains, sugars, and fats,' as well as intake of more calories and inclusion of food additives. There is empirical support for this. For example, a 2024 review of the evidence, which included dozens of analyses, linked 'higher consumption of ultra-processed foods to poor cardiometabolic health, increasing the risk of obesity, type 2 diabetes, dyslipidemia, and cardiovascular disease.' At the same time, the scientific evidence for how ultra-processed foods affect our health isn't unequivocal. In fact, according to a story by the New Scientist covering a recent meeting of the American Society for Nutrition, scientists don't agree that simply opting for less processed foods guarantees a healthy diet. Additionally, former Director of FDA's Center for Food Safety and Applied Nutrition during the Obama, Trump, and Biden administrations from 2015 to 2023, Susan Mayne, says the report omits other well-accepted drivers of chronic disease, such as high intake of sodium and saturated fat. Instead, it criticizes the current set of U.S. dietary guidelines for 'problematic reductionist recommendations' in reference to advice to 'reduce saturated fat' or 'limit sodium.' But in the case of sodium, this seems to ignore decades of research showing that sodium is over-consumed in the U.S., contributing to chronic disease. There are other conspicuous apparent oversights regarding HHS policy. For instance, STAT News notes that the MAHA Commission report includes no mentions of eating disorders such as anorexia nervosa, bulimia nervosa or binge-eating. Such eating disorders have been on the rise for decades, especially among young women and girls. Evidently, research on these eating disorders is being disproportionately affected by ongoing federal grant terminations, according to experts in the field. Also, Reuters reports that despite rising levels of alcoholism, which is conducive to a myriad of chronic diseases, revisions to the U.S. dietary guidelines under RFK Jr. may loosen federal guidance on alcohol consumption that currently advises no more than one to two daily drinks.
Bloomberg
37 minutes ago
- Bloomberg
Democrats Push Back on Cuts to Medicaid, SNAP benefits
Suzan DelBene, democrat congresswoman from Washington and chair of the DCCC, says that potential cuts to Medicaid and nutritional assistance in the Trump tax bill could spur backlash and allow Democrats to retake control of the House in the midterm elections. (Source: Bloomberg)
